/**
 * @license
 * Copyright 2012 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @fileoverview Procedure blocks for Blockly.
 * @suppress {checkTypes|visibility}
 */
'use strict';

goog.module('Blockly.blocks.procedures');

/* eslint-disable-next-line no-unused-vars */
const AbstractEvent = goog.requireType('Blockly.Events.Abstract');
const ContextMenu = goog.require('Blockly.ContextMenu');
const Events = goog.require('Blockly.Events');
const Procedures = goog.require('Blockly.Procedures');
const Variables = goog.require('Blockly.Variables');
const Xml = goog.require('Blockly.Xml');
const internalConstants = goog.require('Blockly.internalConstants');
const xmlUtils = goog.require('Blockly.utils.xml');
const { Align } = goog.require('Blockly.Input');
/* eslint-disable-next-line no-unused-vars */
const { Block } = goog.requireType('Blockly.Block');
const { Blocks } = goog.require('Blockly.blocks');
/* eslint-disable-next-line no-unused-vars */
const { FieldCheckbox } = goog.require('Blockly.FieldCheckbox');
const { FieldLabel } = goog.require('Blockly.FieldLabel');
const { FieldTextInput } = goog.require('Blockly.FieldTextInput');
const { Msg } = goog.require('Blockly.Msg');
const { Mutator } = goog.require('Blockly.Mutator');
const { Names } = goog.require('Blockly.Names');
/* eslint-disable-next-line no-unused-vars */
const { VariableModel } = goog.requireType('Blockly.VariableModel');
/* eslint-disable-next-line no-unused-vars */
const { Workspace } = goog.requireType('Blockly.Workspace');
/** @suppress {extraRequire} */
goog.require('Blockly.Comment');
/** @suppress {extraRequire} */
goog.require('Blockly.Warning');

/**
 * Common properties for the procedure_defnoreturn and
 * procedure_defreturn blocks.
 */
const PROCEDURE_DEF_COMMON = {
    /**
     * Add or remove the statement block from this function definition.
     * @param {boolean} hasStatements True if a statement block is needed.
     * @this {Block}
     */
    setStatements_: function (hasStatements) {
        if (this.hasStatements_ === hasStatements) {
            return;
        }
        if (hasStatements) {
            this.appendStatementInput('STACK').appendField(Msg['PROCEDURES_DEFNORETURN_DO']);
            if (this.getInput('RETURN')) {
                this.moveInputBefore('STACK', 'RETURN');
            }
        } else {
            this.removeInput('STACK', true);
        }
        this.hasStatements_ = hasStatements;
    },
    /**
     * Update the display of parameters for this procedure definition block.
     * @private
     * @this {Block}
     */
    updateParams_: function () {
        // Merge the arguments into a human-readable list.
        let paramString = '';
        if (this.arguments_.length) {
            paramString = Msg['PROCEDURES_BEFORE_PARAMS'] + ' ' + this.arguments_.join(', ');
        }
        // The params field is deterministic based on the mutation,
        // no need to fire a change event.
        Events.disable();
        try {
            this.setFieldValue(paramString, 'PARAMS');
        } finally {
            Events.enable();
        }
    },
    /**
     * Create XML to represent the argument inputs.
     * Backwards compatible serialization implementation.
     * @param {boolean=} opt_paramIds If true include the IDs of the parameter
     *     quarks.  Used by Procedures.mutateCallers for reconnection.
     * @return {!Element} XML storage element.
     * @this {Block}
     */
    mutationToDom: function (opt_paramIds) {
        const container = xmlUtils.createElement('mutation');
        if (opt_paramIds) {
            container.setAttribute('name', this.getFieldValue('NAME'));
        }
        for (let i = 0; i < this.argumentVarModels_.length; i++) {
            const parameter = xmlUtils.createElement('arg');
            const argModel = this.argumentVarModels_[i];
            parameter.setAttribute('name', argModel.name);
            parameter.setAttribute('varid', argModel.getId());
            if (opt_paramIds && this.paramIds_) {
                parameter.setAttribute('paramId', this.paramIds_[i]);
            }
            container.appendChild(parameter);
        }

        // Save whether the statement input is visible.
        if (!this.hasStatements_) {
            container.setAttribute('statements', 'false');
        }
        return container;
    },
    /**
     * Parse XML to restore the argument inputs.
     * Backwards compatible serialization implementation.
     * @param {!Element} xmlElement XML storage element.
     * @this {Block}
     */
    domToMutation: function (xmlElement) {
        this.arguments_ = [];
        this.argumentVarModels_ = [];
        for (let i = 0, childNode; (childNode = xmlElement.childNodes[i]); i++) {
            if (childNode.nodeName.toLowerCase() === 'arg') {
                const varName = childNode.getAttribute('name');
                const varId = childNode.getAttribute('varid') || childNode.getAttribute('varId');
                this.arguments_.push(varName);
                const variable = Variables.getOrCreateVariablePackage(this.workspace, varId, varName, '');
                if (variable !== null) {
                    this.argumentVarModels_.push(variable);
                } else {
                    console.log('Failed to create a variable with name ' + varName + ', ignoring.');
                }
            }
        }
        this.updateParams_();
        Procedures.mutateCallers(this);

        // Show or hide the statement input.
        this.setStatements_(xmlElement.getAttribute('statements') !== 'false');
    },
    /**
     * Returns the state of this block as a JSON serializable object.
     * @return {?{params: (!Array<{name: string, id: string}>|undefined),
     *     hasStatements: (boolean|undefined)}} The state of this block, eg the
     *     parameters and statements.
     */
    saveExtraState: function () {
        if (!this.argumentVarModels_.length && this.hasStatements_) {
            return null;
        }
        const state = Object.create(null);
        if (this.argumentVarModels_.length) {
            state['params'] = [];
            for (let i = 0; i < this.argumentVarModels_.length; i++) {
                state['params'].push({
                    // We don't need to serialize the name, but just in case we decide
                    // to separate params from variables.
                    name: this.argumentVarModels_[i].name,
                    id: this.argumentVarModels_[i].getId()
                });
            }
        }
        if (!this.hasStatements_) {
            state['hasStatements'] = false;
        }
        return state;
    },
    /**
     * Applies the given state to this block.
     * @param {*} state The state to apply to this block, eg the parameters and
     *     statements.
     */
    loadExtraState: function (state) {
        this.arguments_ = [];
        this.argumentVarModels_ = [];
        if (state['params']) {
            for (let i = 0; i < state['params'].length; i++) {
                const param = state['params'][i];
                const variable = Variables.getOrCreateVariablePackage(this.workspace, param['id'], param['name'], '');
                this.arguments_.push(variable.name);
                this.argumentVarModels_.push(variable);
            }
        }
        this.updateParams_();
        Procedures.mutateCallers(this);
        this.setStatements_(state['hasStatements'] === false ? false : true);
    },
    /**
     * Populate the mutator's dialog with this block's components.
     * @param {!Workspace} workspace Mutator's workspace.
     * @return {!Block} Root block in mutator.
     * @this {Block}
     */
    decompose: function (workspace) {
        /*
         * Creates the following XML:
         * <block type="procedures_mutatorcontainer">
         *   <statement name="STACK">
         *     <block type="procedures_mutatorarg">
         *       <field name="NAME">arg1_name</field>
         *       <next>etc...</next>
         *     </block>
         *   </statement>
         * </block>
         */

        const containerBlockNode = xmlUtils.createElement('block');
        containerBlockNode.setAttribute('type', 'procedures_mutatorcontainer');
        const statementNode = xmlUtils.createElement('statement');
        statementNode.setAttribute('name', 'STACK');
        containerBlockNode.appendChild(statementNode);

        let node = statementNode;
        for (let i = 0; i < this.arguments_.length; i++) {
            const argBlockNode = xmlUtils.createElement('block');
            argBlockNode.setAttribute('type', 'procedures_mutatorarg');
            const fieldNode = xmlUtils.createElement('field');
            fieldNode.setAttribute('name', 'NAME');
            const argumentName = xmlUtils.createTextNode(this.arguments_[i]);
            fieldNode.appendChild(argumentName);
            argBlockNode.appendChild(fieldNode);
            const nextNode = xmlUtils.createElement('next');
            argBlockNode.appendChild(nextNode);

            node.appendChild(argBlockNode);
            node = nextNode;
        }

        const containerBlock = Xml.domToBlock(containerBlockNode, workspace);

        if (this.type === 'procedures_defreturn') {
            containerBlock.setFieldValue(this.hasStatements_, 'STATEMENTS');
        } else {
            containerBlock.removeInput('STATEMENT_INPUT');
        }

        // Initialize procedure's callers with blank IDs.
        Procedures.mutateCallers(this);
        return containerBlock;
    },
    /**
     * Reconfigure this block based on the mutator dialog's components.
     * @param {!Block} containerBlock Root block in mutator.
     * @this {Block}
     */
    compose: function (containerBlock) {
        // Parameter list.
        this.arguments_ = [];
        this.paramIds_ = [];
        this.argumentVarModels_ = [];
        let paramBlock = containerBlock.getInputTargetBlock('STACK');
        while (paramBlock && !paramBlock.isInsertionMarker()) {
            const varName = paramBlock.getFieldValue('NAME');
            this.arguments_.push(varName);
            const variable = this.workspace.getVariable(varName, '');
            this.argumentVarModels_.push(variable);

            this.paramIds_.push(paramBlock.id);
            paramBlock = paramBlock.nextConnection && paramBlock.nextConnection.targetBlock();
        }
        this.updateParams_();
        Procedures.mutateCallers(this);

        // Show/hide the statement input.
        let hasStatements = containerBlock.getFieldValue('STATEMENTS');
        if (hasStatements !== null) {
            hasStatements = hasStatements === 'TRUE';
            if (this.hasStatements_ !== hasStatements) {
                if (hasStatements) {
                    this.setStatements_(true);
                    // Restore the stack, if one was saved.
                    Mutator.reconnect(this.statementConnection_, this, 'STACK');
                    this.statementConnection_ = null;
                } else {
                    // Save the stack, then disconnect it.
                    const stackConnection = this.getInput('STACK').connection;
                    this.statementConnection_ = stackConnection.targetConnection;
                    if (this.statementConnection_) {
                        const stackBlock = stackConnection.targetBlock();
                        stackBlock.unplug();
                        stackBlock.bumpNeighbours();
                    }
                    this.setStatements_(false);
                }
            }
        }
    },
    /**
     * Return all variables referenced by this block.
     * @return {!Array<string>} List of variable names.
     * @this {Block}
     */
    getVars: function () {
        return this.arguments_;
    },
    /**
     * Return all variables referenced by this block.
     * @return {!Array<!VariableModel>} List of variable models.
     * @this {Block}
     */
    getVarModels: function () {
        return this.argumentVarModels_;
    },
    /**
     * Notification that a variable is renaming.
     * If the ID matches one of this block's variables, rename it.
     * @param {string} oldId ID of variable to rename.
     * @param {string} newId ID of new variable.  May be the same as oldId, but
     *     with an updated name.  Guaranteed to be the same type as the old
     *     variable.
     * @override
     * @this {Block}
     */
    renameVarById: function (oldId, newId) {
        const oldVariable = this.workspace.getVariableById(oldId);
        if (oldVariable.type !== '') {
            // Procedure arguments always have the empty type.
            return;
        }
        const oldName = oldVariable.name;
        const newVar = this.workspace.getVariableById(newId);

        let change = false;
        for (let i = 0; i < this.argumentVarModels_.length; i++) {
            if (this.argumentVarModels_[i].getId() === oldId) {
                this.arguments_[i] = newVar.name;
                this.argumentVarModels_[i] = newVar;
                change = true;
            }
        }
        if (change) {
            this.displayRenamedVar_(oldName, newVar.name);
            Procedures.mutateCallers(this);
        }
    },
    /**
     * Notification that a variable is renaming but keeping the same ID.  If the
     * variable is in use on this block, rerender to show the new name.
     * @param {!VariableModel} variable The variable being renamed.
     * @package
     * @override
     * @this {Block}
     */
    updateVarName: function (variable) {
        const newName = variable.name;
        let change = false;
        let oldName;
        for (let i = 0; i < this.argumentVarModels_.length; i++) {
            if (this.argumentVarModels_[i].getId() === variable.getId()) {
                oldName = this.arguments_[i];
                this.arguments_[i] = newName;
                change = true;
            }
        }
        if (change) {
            this.displayRenamedVar_(oldName, newName);
            Procedures.mutateCallers(this);
        }
    },
    /**
     * Update the display to reflect a newly renamed argument.
     * @param {string} oldName The old display name of the argument.
     * @param {string} newName The new display name of the argument.
     * @private
     * @this {Block}
     */
    displayRenamedVar_: function (oldName, newName) {
        this.updateParams_();
        // Update the mutator's variables if the mutator is open.
        if (this.mutator && this.mutator.isVisible()) {
            const blocks = this.mutator.workspace_.getAllBlocks(false);
            for (let i = 0, block; (block = blocks[i]); i++) {
                if (block.type === 'procedures_mutatorarg' && Names.equals(oldName, block.getFieldValue('NAME'))) {
                    block.setFieldValue(newName, 'NAME');
                }
            }
        }
    },
    /**
     * Add custom menu options to this block's context menu.
     * @param {!Array} options List of menu options to add to.
     * @this {Block}
     */
    customContextMenu: function (options) {
        if (this.isInFlyout) {
            return;
        }
        // Add option to create caller.
        const option = { enabled: true };
        const name = this.getFieldValue('NAME');
        option.text = Msg['PROCEDURES_CREATE_DO'].replace('%1', name);
        const xmlMutation = xmlUtils.createElement('mutation');
        xmlMutation.setAttribute('name', name);
        for (let i = 0; i < this.arguments_.length; i++) {
            const xmlArg = xmlUtils.createElement('arg');
            xmlArg.setAttribute('name', this.arguments_[i]);
            xmlMutation.appendChild(xmlArg);
        }
        const xmlBlock = xmlUtils.createElement('block');
        xmlBlock.setAttribute('type', this.callType_);
        xmlBlock.appendChild(xmlMutation);
        option.callback = ContextMenu.callbackFactory(this, xmlBlock);
        options.push(option);

        // Add options to create getters for each parameter.
        if (!this.isCollapsed()) {
            for (let i = 0; i < this.argumentVarModels_.length; i++) {
                const argOption = { enabled: true };
                const argVar = this.argumentVarModels_[i];
                argOption.text = Msg['VARIABLES_SET_CREATE_GET'].replace('%1', argVar.name);

                const argXmlField = Variables.generateVariableFieldDom(argVar);
                const argXmlBlock = xmlUtils.createElement('block');
                argXmlBlock.setAttribute('type', 'variables_get');
                argXmlBlock.appendChild(argXmlField);
                argOption.callback = ContextMenu.callbackFactory(this, argXmlBlock);
                options.push(argOption);
            }
        }
    },
    callType_: 'procedures_callnoreturn'
};

Blocks['procedures_defnoreturn'] = {
    ...PROCEDURE_DEF_COMMON,
    /**
     * Block for defining a procedure with no return value.
     * @this {Block}
     */
    init: function () {
        const initName = Procedures.findLegalName('', this);
        const nameField = new FieldTextInput(initName, Procedures.rename);
        nameField.setSpellcheck(false);
        this.appendDummyInput().appendField(Msg['PROCEDURES_DEFNORETURN_TITLE']).appendField(nameField, 'NAME').appendField('', 'PARAMS');
        this.setMutator(new Mutator(['procedures_mutatorarg']));
        if ((this.workspace.options.comments || (this.workspace.options.parentWorkspace && this.workspace.options.parentWorkspace.options.comments)) && Msg['PROCEDURES_DEFNORETURN_COMMENT']) {
            this.setCommentText(Msg['PROCEDURES_DEFNORETURN_COMMENT']);
        }
        this.setStyle('procedure_blocks');
        this.setTooltip(Msg['PROCEDURES_DEFNORETURN_TOOLTIP']);
        this.setHelpUrl(Msg['PROCEDURES_DEFNORETURN_HELPURL']);
        this.arguments_ = [];
        this.argumentVarModels_ = [];
        this.setStatements_(true);
        this.statementConnection_ = null;
    },
    /**
     * Return the signature of this procedure definition.
     * @return {!Array} Tuple containing three elements:
     *     - the name of the defined procedure,
     *     - a list of all its arguments,
     *     - that it DOES NOT have a return value.
     * @this {Block}
     */
    getProcedureDef: function () {
        return [this.getFieldValue('NAME'), this.arguments_, false];
    }
};

Blocks['procedures_defreturn'] = {
    ...PROCEDURE_DEF_COMMON,
    /**
     * Block for defining a procedure with a return value.
     * @this {Block}
     */
    init: function () {
        const initName = Procedures.findLegalName('', this);
        const nameField = new FieldTextInput(initName, Procedures.rename);
        nameField.setSpellcheck(false);
        this.appendDummyInput().appendField(Msg['PROCEDURES_DEFRETURN_TITLE']).appendField(nameField, 'NAME').appendField('', 'PARAMS');
        this.appendValueInput('RETURN').setAlign(Align.RIGHT).appendField(Msg['PROCEDURES_DEFRETURN_RETURN']);
        this.setMutator(new Mutator(['procedures_mutatorarg']));
        if ((this.workspace.options.comments || (this.workspace.options.parentWorkspace && this.workspace.options.parentWorkspace.options.comments)) && Msg['PROCEDURES_DEFRETURN_COMMENT']) {
            this.setCommentText(Msg['PROCEDURES_DEFRETURN_COMMENT']);
        }
        this.setStyle('procedure_blocks');
        this.setTooltip(Msg['PROCEDURES_DEFRETURN_TOOLTIP']);
        this.setHelpUrl(Msg['PROCEDURES_DEFRETURN_HELPURL']);
        this.arguments_ = [];
        this.argumentVarModels_ = [];
        this.setStatements_(true);
        this.statementConnection_ = null;
    },
    /**
     * Return the signature of this procedure definition.
     * @return {!Array} Tuple containing three elements:
     *     - the name of the defined procedure,
     *     - a list of all its arguments,
     *     - that it DOES have a return value.
     * @this {Block}
     */
    getProcedureDef: function () {
        return [this.getFieldValue('NAME'), this.arguments_, true];
    }
};

Blocks['procedures_mutatorcontainer'] = {
    /**
     * Mutator block for procedure container.
     * @this {Block}
     */
    init: function () {
        this.appendDummyInput().appendField(Msg['PROCEDURES_MUTATORCONTAINER_TITLE']);
        this.appendStatementInput('STACK');
        this.appendDummyInput('STATEMENT_INPUT').appendField(Msg['PROCEDURES_ALLOW_STATEMENTS']).appendField(new FieldCheckbox('TRUE'), 'STATEMENTS');
        this.setStyle('procedure_blocks');
        this.setTooltip(Msg['PROCEDURES_MUTATORCONTAINER_TOOLTIP']);
        this.contextMenu = false;
    }
};

Blocks['procedures_mutatorarg'] = {
    /**
     * Mutator block for procedure argument.
     * @this {Block}
     */
    init: function () {
        const field = new FieldTextInput(Procedures.DEFAULT_ARG, this.validator_);
        // Hack: override showEditor to do just a little bit more work.
        // We don't have a good place to hook into the start of a text edit.
        field.oldShowEditorFn_ = field.showEditor_;
        /**
         * @this {FieldTextInput}
         */
        const newShowEditorFn = function () {
            this.createdVariables_ = [];
            this.oldShowEditorFn_();
        };
        field.showEditor_ = newShowEditorFn;

        this.appendDummyInput().appendField(Msg['PROCEDURES_MUTATORARG_TITLE']).appendField(field, 'NAME');
        this.setPreviousStatement(true);
        this.setNextStatement(true);
        this.setStyle('procedure_blocks');
        this.setTooltip(Msg['PROCEDURES_MUTATORARG_TOOLTIP']);
        this.contextMenu = false;

        // Create the default variable when we drag the block in from the flyout.
        // Have to do this after installing the field on the block.
        field.onFinishEditing_ = this.deleteIntermediateVars_;
        // Create an empty list so onFinishEditing_ has something to look at, even
        // though the editor was never opened.
        field.createdVariables_ = [];
        field.onFinishEditing_('x');
    },

    /**
     * Obtain a valid name for the procedure argument. Create a variable if
     * necessary.
     * Merge runs of whitespace.  Strip leading and trailing whitespace.
     * Beyond this, all names are legal.
     * @param {string} varName User-supplied name.
     * @return {?string} Valid name, or null if a name was not specified.
     * @private
     * @this {FieldTextInput}
     */
    validator_: function (varName) {
        const sourceBlock = this.getSourceBlock();
        const outerWs = Mutator.findParentWs(sourceBlock.workspace);
        varName = varName.replace(/[\s\xa0]+/g, ' ').replace(/^ | $/g, '');
        if (!varName) {
            return null;
        }

        // Prevents duplicate parameter names in functions
        const workspace = sourceBlock.workspace.targetWorkspace || sourceBlock.workspace;
        const blocks = workspace.getAllBlocks(false);
        const caselessName = varName.toLowerCase();
        for (let i = 0; i < blocks.length; i++) {
            if (blocks[i].id === this.getSourceBlock().id) {
                continue;
            }
            // Other blocks values may not be set yet when this is loaded.
            const otherVar = blocks[i].getFieldValue('NAME');
            if (otherVar && otherVar.toLowerCase() === caselessName) {
                return null;
            }
        }

        // Don't create variables for arg blocks that
        // only exist in the mutator's flyout.
        if (sourceBlock.isInFlyout) {
            return varName;
        }

        let model = outerWs.getVariable(varName, '');
        if (model && model.name !== varName) {
            // Rename the variable (case change)
            outerWs.renameVariableById(model.getId(), varName);
        }
        if (!model) {
            model = outerWs.createVariable(varName, '');
            if (model && this.createdVariables_) {
                this.createdVariables_.push(model);
            }
        }
        return varName;
    },

    /**
     * Called when focusing away from the text field.
     * Deletes all variables that were created as the user typed their intended
     * variable name.
     * @param {string} newText The new variable name.
     * @private
     * @this {FieldTextInput}
     */
    deleteIntermediateVars_: function (newText) {
        const outerWs = Mutator.findParentWs(this.getSourceBlock().workspace);
        if (!outerWs) {
            return;
        }
        for (let i = 0; i < this.createdVariables_.length; i++) {
            const model = this.createdVariables_[i];
            if (model.name !== newText) {
                outerWs.deleteVariableById(model.getId());
            }
        }
    }
};

/**
 * Common properties for the procedure_callnoreturn and
 * procedure_callreturn blocks.
 */
const PROCEDURE_CALL_COMMON = {
    /**
     * Returns the name of the procedure this block calls.
     * @return {string} Procedure name.
     * @this {Block}
     */
    getProcedureCall: function () {
        // The NAME field is guaranteed to exist, null will never be returned.
        return /** @type {string} */ (this.getFieldValue('NAME'));
    },
    /**
     * Notification that a procedure is renaming.
     * If the name matches this block's procedure, rename it.
     * @param {string} oldName Previous name of procedure.
     * @param {string} newName Renamed procedure.
     * @this {Block}
     */
    renameProcedure: function (oldName, newName) {
        if (Names.equals(oldName, this.getProcedureCall())) {
            this.setFieldValue(newName, 'NAME');
            const baseMsg = this.outputConnection ? Msg['PROCEDURES_CALLRETURN_TOOLTIP'] : Msg['PROCEDURES_CALLNORETURN_TOOLTIP'];
            this.setTooltip(baseMsg.replace('%1', newName));
        }
    },
    /**
     * Notification that the procedure's parameters have changed.
     * @param {!Array<string>} paramNames New param names, e.g. ['x', 'y', 'z'].
     * @param {!Array<string>} paramIds IDs of params (consistent for each
     *     parameter through the life of a mutator, regardless of param renaming),
     *     e.g. ['piua', 'f8b_', 'oi.o'].
     * @private
     * @this {Block}
     */
    setProcedureParameters_: function (paramNames, paramIds) {
        // Data structures:
        // this.arguments = ['x', 'y']
        //     Existing param names.
        // this.quarkConnections_ {piua: null, f8b_: Connection}
        //     Look-up of paramIds to connections plugged into the call block.
        // this.quarkIds_ = ['piua', 'f8b_']
        //     Existing param IDs.
        // Note that quarkConnections_ may include IDs that no longer exist, but
        // which might reappear if a param is reattached in the mutator.
        const defBlock = Procedures.getDefinition(this.getProcedureCall(), this.workspace);
        const mutatorOpen = defBlock && defBlock.mutator && defBlock.mutator.isVisible();
        if (!mutatorOpen) {
            this.quarkConnections_ = {};
            this.quarkIds_ = null;
        }
        if (!paramIds) {
            // Reset the quarks (a mutator is about to open).
            return;
        }
        // Test arguments (arrays of strings) for changes. '\n' is not a valid
        // argument name character, so it is a valid delimiter here.
        if (paramNames.join('\n') === this.arguments_.join('\n')) {
            // No change.
            this.quarkIds_ = paramIds;
            return;
        }
        if (paramIds.length !== paramNames.length) {
            throw RangeError('paramNames and paramIds must be the same length.');
        }
        this.setCollapsed(false);
        if (!this.quarkIds_) {
            // Initialize tracking for this block.
            this.quarkConnections_ = {};
            this.quarkIds_ = [];
        }
        // Switch off rendering while the block is rebuilt.
        const savedRendered = this.rendered;
        this.rendered = false;
        // Update the quarkConnections_ with existing connections.
        for (let i = 0; i < this.arguments_.length; i++) {
            const input = this.getInput('ARG' + i);
            if (input) {
                const connection = input.connection.targetConnection;
                this.quarkConnections_[this.quarkIds_[i]] = connection;
                if (mutatorOpen && connection && paramIds.indexOf(this.quarkIds_[i]) === -1) {
                    // This connection should no longer be attached to this block.
                    connection.disconnect();
                    connection.getSourceBlock().bumpNeighbours();
                }
            }
        }
        // Rebuild the block's arguments.
        this.arguments_ = [].concat(paramNames);
        // And rebuild the argument model list.
        this.argumentVarModels_ = [];
        for (let i = 0; i < this.arguments_.length; i++) {
            const variable = Variables.getOrCreateVariablePackage(this.workspace, null, this.arguments_[i], '');
            this.argumentVarModels_.push(variable);
        }

        this.updateShape_();
        this.quarkIds_ = paramIds;
        // Reconnect any child blocks.
        if (this.quarkIds_) {
            for (let i = 0; i < this.arguments_.length; i++) {
                const quarkId = this.quarkIds_[i];
                if (quarkId in this.quarkConnections_) {
                    const connection = this.quarkConnections_[quarkId];
                    if (!Mutator.reconnect(connection, this, 'ARG' + i)) {
                        // Block no longer exists or has been attached elsewhere.
                        delete this.quarkConnections_[quarkId];
                    }
                }
            }
        }
        // Restore rendering and show the changes.
        this.rendered = savedRendered;
        if (this.rendered) {
            this.render();
        }
    },
    /**
     * Modify this block to have the correct number of arguments.
     * @private
     * @this {Block}
     */
    updateShape_: function () {
        for (let i = 0; i < this.arguments_.length; i++) {
            const argField = this.getField('ARGNAME' + i);
            if (argField) {
                // Ensure argument name is up to date.
                // The argument name field is deterministic based on the mutation,
                // no need to fire a change event.
                Events.disable();
                try {
                    argField.setValue(this.arguments_[i]);
                } finally {
                    Events.enable();
                }
            } else {
                // Add new input.
                const newField = new FieldLabel(this.arguments_[i]);
                const input = this.appendValueInput('ARG' + i)
                    .setAlign(Align.RIGHT)
                    .appendField(newField, 'ARGNAME' + i);
                input.init();
            }
        }
        // Remove deleted inputs.
        for (let i = this.arguments_.length; this.getInput('ARG' + i); i++) {
            this.removeInput('ARG' + i);
        }
        // Add 'with:' if there are parameters, remove otherwise.
        const topRow = this.getInput('TOPROW');
        if (topRow) {
            if (this.arguments_.length) {
                if (!this.getField('WITH')) {
                    topRow.appendField(Msg['PROCEDURES_CALL_BEFORE_PARAMS'], 'WITH');
                    topRow.init();
                }
            } else {
                if (this.getField('WITH')) {
                    topRow.removeField('WITH');
                }
            }
        }
    },
    /**
     * Create XML to represent the (non-editable) name and arguments.
     * Backwards compatible serialization implementation.
     * @return {!Element} XML storage element.
     * @this {Block}
     */
    mutationToDom: function () {
        const container = xmlUtils.createElement('mutation');
        container.setAttribute('name', this.getProcedureCall());
        for (let i = 0; i < this.arguments_.length; i++) {
            const parameter = xmlUtils.createElement('arg');
            parameter.setAttribute('name', this.arguments_[i]);
            container.appendChild(parameter);
        }
        return container;
    },
    /**
     * Parse XML to restore the (non-editable) name and parameters.
     * Backwards compatible serialization implementation.
     * @param {!Element} xmlElement XML storage element.
     * @this {Block}
     */
    domToMutation: function (xmlElement) {
        const name = xmlElement.getAttribute('name');
        this.renameProcedure(this.getProcedureCall(), name);
        const args = [];
        const paramIds = [];
        for (let i = 0, childNode; (childNode = xmlElement.childNodes[i]); i++) {
            if (childNode.nodeName.toLowerCase() === 'arg') {
                args.push(childNode.getAttribute('name'));
                paramIds.push(childNode.getAttribute('paramId'));
            }
        }
        this.setProcedureParameters_(args, paramIds);
    },
    /**
     * Returns the state of this block as a JSON serializable object.
     * @return {{name: string, params:(!Array<string>|undefined)}} The state of
     *     this block, ie the params and procedure name.
     */
    saveExtraState: function () {
        const state = Object.create(null);
        state['name'] = this.getProcedureCall();
        if (this.arguments_.length) {
            state['params'] = this.arguments_;
        }
        return state;
    },
    /**
     * Applies the given state to this block.
     * @param {*} state The state to apply to this block, ie the params and
     *     procedure name.
     */
    loadExtraState: function (state) {
        this.renameProcedure(this.getProcedureCall(), state['name']);
        const params = state['params'];
        if (params) {
            const ids = [];
            ids.length = params.length;
            ids.fill(null);
            this.setProcedureParameters_(params, ids);
        }
    },
    /**
     * Return all variables referenced by this block.
     * @return {!Array<string>} List of variable names.
     * @this {Block}
     */
    getVars: function () {
        return this.arguments_;
    },
    /**
     * Return all variables referenced by this block.
     * @return {!Array<!VariableModel>} List of variable models.
     * @this {Block}
     */
    getVarModels: function () {
        return this.argumentVarModels_;
    },
    /**
     * Procedure calls cannot exist without the corresponding procedure
     * definition.  Enforce this link whenever an event is fired.
     * @param {!AbstractEvent} event Change event.
     * @this {Block}
     */
    onchange: function (event) {
        if (!this.workspace || this.workspace.isFlyout) {
            // Block is deleted or is in a flyout.
            return;
        }
        if (!event.recordUndo) {
            // Events not generated by user. Skip handling.
            return;
        }
        if (event.type === Events.BLOCK_CREATE && event.ids.indexOf(this.id) !== -1) {
            // Look for the case where a procedure call was created (usually through
            // paste) and there is no matching definition.  In this case, create
            // an empty definition block with the correct signature.
            const name = this.getProcedureCall();
            let def = Procedures.getDefinition(name, this.workspace);
            if (def && (def.type !== this.defType_ || JSON.stringify(def.getVars()) !== JSON.stringify(this.arguments_))) {
                // The signatures don't match.
                def = null;
            }
            if (!def) {
                Events.setGroup(event.group);
                /**
                 * Create matching definition block.
                 * <xml xmlns="https://developers.google.com/blockly/xml">
                 *   <block type="procedures_defreturn" x="10" y="20">
                 *     <mutation name="test">
                 *       <arg name="x"></arg>
                 *     </mutation>
                 *     <field name="NAME">test</field>
                 *   </block>
                 * </xml>
                 */
                const xml = xmlUtils.createElement('xml');
                const block = xmlUtils.createElement('block');
                block.setAttribute('type', this.defType_);
                const xy = this.getRelativeToSurfaceXY();
                const x = xy.x + internalConstants.SNAP_RADIUS * (this.RTL ? -1 : 1);
                const y = xy.y + internalConstants.SNAP_RADIUS * 2;
                block.setAttribute('x', x);
                block.setAttribute('y', y);
                const mutation = this.mutationToDom();
                block.appendChild(mutation);
                const field = xmlUtils.createElement('field');
                field.setAttribute('name', 'NAME');
                let callName = this.getProcedureCall();
                if (!callName) {
                    // Rename if name is empty string.
                    callName = Procedures.findLegalName('', this);
                    this.renameProcedure('', callName);
                }
                field.appendChild(xmlUtils.createTextNode(callName));
                block.appendChild(field);
                xml.appendChild(block);
                Xml.domToWorkspace(xml, this.workspace);
                Events.setGroup(false);
            }
        } else if (event.type === Events.BLOCK_DELETE) {
            // Look for the case where a procedure definition has been deleted,
            // leaving this block (a procedure call) orphaned.  In this case, delete
            // the orphan.
            const name = this.getProcedureCall();
            const def = Procedures.getDefinition(name, this.workspace);
            if (!def) {
                Events.setGroup(event.group);
                this.dispose(true);
                Events.setGroup(false);
            }
        } else if (event.type === Events.CHANGE && event.element === 'disabled') {
            const name = this.getProcedureCall();
            const def = Procedures.getDefinition(name, this.workspace);
            if (def && def.id === event.blockId) {
                // in most cases the old group should be ''
                const oldGroup = Events.getGroup();
                if (oldGroup) {
                    // This should only be possible programmatically and may indicate a
                    // problem with event grouping. If you see this message please
                    // investigate. If the use ends up being valid we may need to reorder
                    // events in the undo stack.
                    console.log('Saw an existing group while responding to a definition change');
                }
                Events.setGroup(event.group);
                if (event.newValue) {
                    this.previousEnabledState_ = this.isEnabled();
                    this.setEnabled(false);
                } else {
                    this.setEnabled(this.previousEnabledState_);
                }
                Events.setGroup(oldGroup);
            }
        }
    },
    /**
     * Add menu option to find the definition block for this call.
     * @param {!Array} options List of menu options to add to.
     * @this {Block}
     */
    customContextMenu: function (options) {
        if (!this.workspace.isMovable()) {
            // If we center on the block and the workspace isn't movable we could
            // loose blocks at the edges of the workspace.
            return;
        }

        const option = { enabled: true };
        option.text = Msg['PROCEDURES_HIGHLIGHT_DEF'];
        const name = this.getProcedureCall();
        const workspace = this.workspace;
        option.callback = function () {
            const def = Procedures.getDefinition(name, workspace);
            if (def) {
                workspace.centerOnBlock(def.id);
                def.select();
            }
        };
        options.push(option);
    }
};

Blocks['procedures_callnoreturn'] = {
    ...PROCEDURE_CALL_COMMON,
    /**
     * Block for calling a procedure with no return value.
     * @this {Block}
     */
    init: function () {
        this.appendDummyInput('TOPROW').appendField('', 'NAME');
        this.setPreviousStatement(true);
        this.setNextStatement(true);
        this.setStyle('procedure_blocks');
        // Tooltip is set in renameProcedure.
        this.setHelpUrl(Msg['PROCEDURES_CALLNORETURN_HELPURL']);
        this.arguments_ = [];
        this.argumentVarModels_ = [];
        this.quarkConnections_ = {};
        this.quarkIds_ = null;
        this.previousEnabledState_ = true;
    },

    defType_: 'procedures_defnoreturn'
};

Blocks['procedures_callreturn'] = {
    ...PROCEDURE_CALL_COMMON,
    /**
     * Block for calling a procedure with a return value.
     * @this {Block}
     */
    init: function () {
        this.appendDummyInput('TOPROW').appendField('', 'NAME');
        this.setOutput(true);
        this.setStyle('procedure_blocks');
        // Tooltip is set in domToMutation.
        this.setHelpUrl(Msg['PROCEDURES_CALLRETURN_HELPURL']);
        this.arguments_ = [];
        this.argumentVarModels_ = [];
        this.quarkConnections_ = {};
        this.quarkIds_ = null;
        this.previousEnabledState_ = true;
    },

    defType_: 'procedures_defreturn'
};

Blocks['procedures_ifreturn'] = {
    /**
     * Block for conditionally returning a value from a procedure.
     * @this {Block}
     */
    init: function () {
        this.appendValueInput('CONDITION').setCheck('Boolean').appendField(Msg['CONTROLS_IF_MSG_IF']);
        this.appendValueInput('VALUE').appendField(Msg['PROCEDURES_DEFRETURN_RETURN']);
        this.setInputsInline(true);
        this.setPreviousStatement(true);
        this.setNextStatement(true);
        this.setStyle('procedure_blocks');
        this.setTooltip(Msg['PROCEDURES_IFRETURN_TOOLTIP']);
        this.setHelpUrl(Msg['PROCEDURES_IFRETURN_HELPURL']);
        this.hasReturnValue_ = true;
    },
    /**
     * Create XML to represent whether this block has a return value.
     * @return {!Element} XML storage element.
     * @this {Block}
     */
    mutationToDom: function () {
        const container = xmlUtils.createElement('mutation');
        container.setAttribute('value', Number(this.hasReturnValue_));
        return container;
    },
    /**
     * Parse XML to restore whether this block has a return value.
     * @param {!Element} xmlElement XML storage element.
     * @this {Block}
     */
    domToMutation: function (xmlElement) {
        const value = xmlElement.getAttribute('value');
        this.hasReturnValue_ = value === '1';
        if (!this.hasReturnValue_) {
            this.removeInput('VALUE');
            this.appendDummyInput('VALUE').appendField(Msg['PROCEDURES_DEFRETURN_RETURN']);
        }
    },

    // This block does not need JSO serialization hooks (saveExtraState and
    // loadExtraState) because the state of this block is already encoded in the
    // block's position in the workspace.
    // XML hooks are kept for backwards compatibility.

    /**
     * Called whenever anything on the workspace changes.
     * Add warning if this flow block is not nested inside a loop.
     * @param {!AbstractEvent} _e Change event.
     * @this {Block}
     */
    onchange: function (_e) {
        if (this.workspace.isDragging && this.workspace.isDragging()) {
            return; // Don't change state at the start of a drag.
        }
        let legal = false;
        // Is the block nested in a procedure?
        let block = this;
        do {
            if (this.FUNCTION_TYPES.indexOf(block.type) !== -1) {
                legal = true;
                break;
            }
            block = block.getSurroundParent();
        } while (block);
        if (legal) {
            // If needed, toggle whether this block has a return value.
            if (block.type === 'procedures_defnoreturn' && this.hasReturnValue_) {
                this.removeInput('VALUE');
                this.appendDummyInput('VALUE').appendField(Msg['PROCEDURES_DEFRETURN_RETURN']);
                this.hasReturnValue_ = false;
            } else if (block.type === 'procedures_defreturn' && !this.hasReturnValue_) {
                this.removeInput('VALUE');
                this.appendValueInput('VALUE').appendField(Msg['PROCEDURES_DEFRETURN_RETURN']);
                this.hasReturnValue_ = true;
            }
            this.setWarningText(null);
            if (!this.isInFlyout) {
                this.setEnabled(true);
            }
        } else {
            this.setWarningText(Msg['PROCEDURES_IFRETURN_WARNING']);
            if (!this.isInFlyout && !this.getInheritedDisabled()) {
                this.setEnabled(false);
            }
        }
    },
    /**
     * List of block types that are functions and thus do not need warnings.
     * To add a new function type add this to your code:
     * Blocks['procedures_ifreturn'].FUNCTION_TYPES.push('custom_func');
     */
    FUNCTION_TYPES: ['procedures_defnoreturn', 'procedures_defreturn']
};
